/**
 *    j_util 1.0
 *	  depend on  jquery1.4
 *
 **/
function checkAll(selfObj,targetCheckbox){
		var expr = ":checkbox[name="+targetCheckbox+"]";
		if(selfObj.checked){
			$(expr).each(function(){
				$(this).attr("checked",true);
			});
		}else{
			$(expr).each(function(){
				$(this).attr("checked",false);
			});
		}	
	}
	
	function getCheckboxVal(targetCheckbox){
		var i = 0;
		var defaultReg =",";
		var expr = ":checkbox[name="+targetCheckbox+"][checked]";
		var checkboxVal ="";
		$(expr).each(function(){
			if(i++!=0)
				checkboxVal+=defaultReg;
			checkboxVal+=$(this).val();
		});
		return checkboxVal;
	}
	
	function getCheckboxLengthByChecked(targetCheckbox){
		var expr = ":checkbox[name="+targetCheckbox+"][checked]";	
		return $(expr).length;
	}
	
	function isMultiChecked(targetCheckbox){
		return getCheckboxLengthByChecked(targetCheckbox)>0;
	}
	
	function isOneChecked(targetCheckbox){		
		return getCheckboxLengthByChecked(targetCheckbox)==1;
	}